Stick dispensers for deodorants, anti-perspirants, medicaments, cosmetics and the like are well-known in the art. One of the most common dispensers includes a generally cylindrical container, open at both the top and the bottom. The top is provided with a detachable cap. A piston is slidably seated within the container, the bottom of the piston being accessible to finger pressure through the open bottom. The stick of dispensable material may be advanced by forcing the piston upwardly toward the top. However, in such a structure it is difficult to force the stick of material downwardly particularly if it is relatively soft.
In order to provide for both advancement and retraction of the stick of dispensable material, a similar container is well-known in the art including a threaded transport shaft which extends along the longitudinal axis of the container. The piston is threadably engaged to the shaft and provided with means to secure it against rotation within the container. A knob is attached to the bottom of the shaft at the bottom of the container. Rotation of the knob induces translational movement on the part of the piston which forces the stick material either upwardly or retracts it downwardly. Such dispensers are commonly known as propel-repel type.
One of the most difficult problems encountered in stick dispensers is the exclusion of air and the prevention of evaporation over a long period of time. Deodorants, antiperspirants and other cosmetics as well as the solid carrier media are subject to air deterioration and evaporation. It is economically impractical to encase dispensers in air-sealed packages. Moreover, if such a package were employed, once the consumer opens the package, air deterioration and evaporation commences.
The fewer the openings in the dispenser, the less the opportunity for air penetration or evaporation of material contained there within which is equally as detrimental if not more so. Dispensers with a manually pushed piston must provide a relatively large opening in the bottom for access to the piston. Both evaporation and air penetration are very substantial. Propel-repel dispensers which include turning knobs at the bottom must necessarily include an opening for mechanical connection of the turning knob with the threaded shaft. Here again evaporation and air penetration is substantial.
Nevertheless, the propel-repel type dispenser is superior to the manually operated push type dispenser because the solid stick can be retracted after use. Additionally, it is desirable to provide a propel-repel type dispenser which can be manipulated by one hand rather than requiring the body of the dispenser to be held by one hand and a turning knob manipulated by the other hand. The one-hand type of manipulation permits advancement of the stick as it is being used if necessary.
Therefore, it is among the objects and advantages of the present invention to provide a propel-repel solid stick dispenser for deodorants, anti-perspirants, medicaments, cosmetics or the like which is secure against deterioration of the dispensable material by virtue of either evaporation from the dispenser or air penetration into the dispenser.
Another object of the present invention is to provide a propel-repel solid stick dispenser of the character aforesaid which can be manipulated to advance or retract the stick by one hand, that spporting the dispenser.
Yet another object of the present invention is to provide a propel-repel solid stick dispenser of the character aforesaid having a cap closure which seals against both evaporation and air penetration without relying upon a seal generated by the inter-engagement of threads on the body of the dispenser and the cap.
Yet still another object of the present invention is to provide a propel-repel solid stick dispenser of the character aforesaid which may be fabricated of inexpensive molded plastic and which may be quickly and easily assembled thereby providing both a functionally superior and inexpensive dispenser.
These objects and advantages as well as other objects and advantages may be achieved by the dispenser claimed herein a preferred embodiment of which is illustrated in the drawings.